Method and apparatus for the simultaneous centralized control of the yarn brakes of twist spindles of a two-for-one twisting machine

ABSTRACT

A method and apparatus for the simultaneous centralized controlled adjustment of the braking force of yarn brakes of a plurality of twist spindles of a two-for-one twisting machine are provided, whereby each twist spindle is of the type having, in its hollow shaft, a yarn brake supported between two brake rings with one of the brake rings being rotatable in response to a downward axial pressure thereon in a manner such that the brake ring undergoes a discrete axial displacement to a new axial position. A support frame to which yarn balloon guides are mounted exerts a downward axial force such that the yarn balloon guides simultaneously exert downward axial pressure on the yarn intake conduits of the twist spindles which, in turn, effects axial displacement of the rotatable and axially adjustable brake ring on the yarn intake conduit of each twist spindle into new axial positions.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a method and apparatus for the simultaneous centralized control of capsule-like yarn brakes of several twist spindles of a two-for-one twisting machine.

[0002] DE 44 08 262 C2 discloses an apparatus for the central control of a capsule-like yarn brake of a twisting machine, especially a two-for-one twisting machine. This conventional apparatus includes a control device and a common compressed air unit which is communicated with the twist spindles via connecting units each associated with a respective twist spindle and operable to deliver air pulses to a pressurized air cylinder coupled to a brake ring of the respective twist spindle, the control device controlling the common compressed air unit to deliver pressurized air pulses to the pressurized air cylinders, whereby the pressurized air cylinders, upon receipt of the air pulses, effect an axial displacement of the rotatable brake rings of all of the capsule-like yarn brakes over a predetermined extent.

[0003] DE PS 32 43 157 discloses a twist spindle having a capsule-like yarn brake, which is supported between upper and lower brake rings. The upper brake ring is mounted to a support body at the lower end of a yarn intake conduit of a twist spindle and is resiliently biased by a spring in the direction of the lower, second brake ring. The support body is provided with a plurality of support shoulders distributed around its circumference at different axial positions so that a respective one of the support shoulders is supported on a stationary detent. An adjustment of the braking force of the capsule-like yarn brake is effected in a manner such that the yarn intake conduit is raised against the force of the spring which biases the support body and, thereafter, the yarn intake conduit is rotated through a pre-determined angular range of traverse such that another support shoulder of the support body comes to rest against the detent. This conventional device is thus directed to an individual adjustment and, especially, a manual individual adjustment, of each individual capsule-like yarn brake.

SUMMARY OF THE INVENTION

[0004] The present invention offers a solution to the challenge of providing a method and an apparatus for the simultaneous centralized controlled adjustment of the capsule-like yarn brakes of a plurality of twist spindles of a two-for-one twisting machine such that the need for a dedicated pressurized air system can be avoided.

[0005] Summarizing the prevalent characteristics of the present invention, the present invention is particularly characterized in that it exerts, in a purely mechanical operation implemented via a plurality of yarn balloon guides commonly supported on a support frame, a sufficiently high pressure on the yarn intake conduits of a plurality of twist spindles such that the yarn intake conduits, which each support one of the two respective brake rings of the respective twist spindle, are axially displaced against the bias of a spring force to an extent such that a brake ring rotation advances the brake ring to a different axial position relative to the other, second respective brake ring following each release of the yarn intake conduit from the axial pressure thereon.

[0006] An embodiment of the present invention is described in the following description taken in connection with the figures of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a sectional view of a two-for-one twisting machine having a plurality of yarn balloon guides commonly mounted on a yarn guide frame, which is movable upwardly and downwardly;

[0008]FIG. 2 is an enlarged sectional view of a twist spindle having a hollow shaft in which a capsule-like yarn brake is disposed;

[0009]FIGS. 3a-3 c are each an enlarged perspective view of a portion of the adjustment unit at a respective different position thereof during movement of the adjustment unit to adjust the braking force of the twist spindle relative to a stationary detent;

[0010]FIG. 4 is an enlarged perspective view of a variation of the one embodiment of the adjustment unit; and

[0011]FIG. 5 is an enlarged perspective view of a twist spindle having a variation of the embodiment of a yarn balloon guide.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012]FIG. 1 shows a sectional view of a two-for-one twisting machine which supports the yarn balloon guides 9 of a plurality of twist spindles S arranged in neighboring relation to one another, the yarn balloon guides 9 being commonly mounted to a common yarn guide frame 11 which is movable—in a not illustrated guide—upwardly and downwardly parallel to the axes of the twist spindles S in the direction of the double arrow F1.

[0013] The yarn guide frame 11 is suspended by means of suspension hangers 12 on a shaft 13, which is rotatably driven by a rotation drive 14 operatively coupled to a motor 15. The downward movement of the yarn guide frame 11 is effected under the influence of gravity by corresponding controlled actuation of the motor 15. The possibility thus exists to position the yarn balloon guides 9 at differing heights over the yarn intake conduits 3, whereby, to exert an influence on the yarn twisting process, the formation of yarn balloons can be controlled. In accordance with the present invention, the yarn balloon guides 9 can be displaced downwardly through corresponding adjustment of the yarn guide frame 11 to such an extent that the yarn balloon guides 9 exert a downward pressure on the yarn intake conduits 3 of a plurality of the twist spindles S, whereby the yarn intake conduits 3 are pressed downwardly. In this manner, as will be hereinafter described, the possibility exists to provide a centrally controlled adjustment of the yarn brakes of a plurality of spindles S arranged in neighboring relationship to one another.

[0014]FIG. 2 shows a portion of the hollow shaft 2 of a rotationally symmetric housing 16 in which is disposed a capsule-like yarn brake 11 and an adjustment unit 18 which is responsive to downward pressure on the yarn intake conduit 3, the adjustment unit 18 being operable to effect a variation of the braking force of the capsule-like yarn brake 11. The adjustment unit 18 is secured to the bottom end of the yarn intake conduit 3 and comprises a cylindrical housing 27 open towards its bottom for receipt therein of a helical spring 28 which biases the adjustment unit 18 upwardly.

[0015] The housing 16 is closed on its topside by a threaded cover 19 through which the yarn intake conduit 3 is guided outwardly of the housing 16. The capsule-like yarn brake 11 includes a bullet-like brake which, in conventional manner, is comprised of two displaceable tube portions 11.1 and 11.2 biased by a spring to move axially away from one another and each of which includes a cup or cap-shaped end portion. The lower tube portion 11.2 is supported against a brake ring 20, which is disposed in a brake ring carrier 21 disposed in an axial guide or groove 21.1. The brake ring carrier 21, which is supported against a helical spring 22, is sealingly guided in a housing bore 16.2 formed in the housing 16 such that, for purposes of effecting a pneumatic yarn threading or intake of yarn, an under-pressure is created below the yarn ring carrier 21 so as to effect downward movement of the yarn ring carrier. The lowered yarn ring 20 thus releases the bullet-like yarn brake 11 to fall whereupon it is then caught by a support ring 16.3 stationarily mounted in the housing; the support ring 16.3 has a partial opening 16.31 such that a yarn introduced through the yarn intake conduit 3 can be suctioned in through the yarn intake 8 into the bore 21.1 and guided past the released bullet-like brake 11. A yarn threading system of this type is described in DE 44 08 262 C2 and is, in any event, the basic configuration of the yarn intake assembly as described in the hereinafter-described adjustment unit 18.

[0016] A first annular upper toothed rim 40 is disposed on the adjustment unit 18 above the housing 27 and a second annular lower tooth rim 41 is disposed above the housing 27 as well. The upwardly directed teeth of the lower toothed rim 41 form therebetween axial spaces in the form of openings/slots whose bases or bottoms form notches or, respectively, support shoulders which are distributed about the circumference of the toothed rim at differing axial heights therearound and each notch or support shoulder is engaged upon its turn by a radially inwardly projecting detent 29 as a function of the rotational position of the adjustment unit 18.

[0017] The downwardly directed teeth of the upper-toothed rim 40 form therebetween axially extending slots opening downwardly or, respectively, form downwardly opening notches.

[0018] Reference is now had to FIGS. 3a-3 c for a description of the configuration of the teeth of the two toothed rims 40 and 41; the arrow F2 indicates the rotational direction of the adjustment unit 18.

[0019] The flanks 40.1 and 41.1 of the teeth of the upper and lower toothed rims 40 and 41 which extend in the rotational direction F2 have substantially axial extents. The down sloping flanks 40.2 or, respectively, 41.2 of the upper and lower toothed rims 40 and 41 are configured as respective rising or falling angled surfaces which form an angle of approximately 45° relative to the rotational direction. The tips or peaks of the teeth of the upper-toothed rim 40 are offset from the tips or peaks of the teeth of the lower toothed rim 41 in the rotational direction by an amount which is slightly greater than the diameter of the detent 29.

[0020]FIG. 3a shows an operational condition in which the lower toothed rim 41 is engaged by the detent 29 such that the detent is seated in a notch I between two neighboring teeth of the lower toothed rim with the portion of the adjustment unit 18 comprised of the lower toothed rim 41 being upwardly biased by the spring 28. If the adjustment unit 18 is displaced downwardly in the direction of the arrow F3 via a downward pressure on the yarn intake conduit 3, the detent initially assumes the position shown by the broken lines 29′ seen in FIG. 3b. Upon further downward pressure on the yarn intake conduit 3, the detent traverses along the toothed flank 40.2 extending away from the rotational direction f2 to thereafter achieve the intermediate position 29″ shown in FIG. 3c in correspondence with the partial rotation of the adjustment unit 18 in the direction of the rotation direction F2. The movement of the detent 29 relative to the adjustment unit 18 follows thus along the path of the bent arrow F5 shown in FIG. 3a. It is to be understood that the stationary detent 29 does not axially change its position but, rather, the adjustment unit 18 undergoes a partial rotation during this process.

[0021] If, thereafter, the yarn intake conduit 3 is again released, the adjustment unit 18 is again biased upwardly, as seen in FIG. 3c, in the direction of the arrow F4 due to the biasing action of the spring 28 so that the detent 29—following the path shown by the bent arrow F6—seats into the next following notch 11, whereby there follows a sliding movement of the detent 29 along the flank 41.2 in the direction of the rotation direction F2 upon a further partial rotation of the adjustment unit 18.

[0022] By virtue of the lowering and subsequent release of the yarn intake conduit 3 and, thus, of the adjustment unit 18, there follows a sectional rotation of the adjustment unit 18 in the rotational direction F2. Since each notch is lower than the immediately preceding notch, it follows, as the detent 29 seats into the respective next following notch, that the brake ring 23 is disposed in progressively lower positions following each operation to lower and release the yarn conduit 3, thus leading to an increase in the braking force.

[0023] The braking force can thus be adjusted in a step-wise manner through individual downward pressure and release sequences of the yarn intake conduit 3 until the braking force has been increased to a maximum value, which value is predetermined by the depth of the deepest notch in the lower toothed rim 41.

[0024] Through multiple sequential actuation—that is, multiple actuation involving downward pressure and release of the yarn intake conduit 3—the yarn braking force can be increased until the detent 29 is eventually seated in the deepest notch of the lower toothed rim 41.

[0025] By sequential or subsequent activation of the yarn intake conduit 3, the detent 29 is moved into the next following—that is—the highest disposed notch—of the lower toothed rim 41, which corresponds to the braking force adjustment position of the lowest value.

[0026] The toothed rims 40′, 41′, as seen in FIG. 4, can be configured as lower components freely rotatable relative to the remainder of the adjustment unit 18 but not, however, adjustable relative thereto in the axial direction, with the toothed rims 40′, 41′ being supported by, from below, a collar of the housing 27 and, from above, a detent body 60 which is securely mounted via, for example, a threaded screw 61, on the yarn intake conduit 3.

[0027] The yarn balloon guides can alternatively be configured to be self-centering with respect to the associated yarn intake conduits 3—e.g., as truncated ball-shaped yarn balloon guides 9′, as seen in FIG. 5.

[0028] The specification incorporates by reference the disclosure of German priority document DE 100 45 909.9.

[0029] The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. 

What I claim is:
 1. A method for the simultaneous centralized controlled adjustment of the braking force of capsule-like yarn brakes of a plurality of twist spindles of a two-for-one twisting machine, whereby each twist spindle includes a bullet-like brake arrangement disposed in the hollow shaft thereof having a capsule-like yarn brake supported between two brake rings disposed at an axial spacing from one another, one of the brake rings being rotatable in response to a downward axial pressure thereon in a manner such that the brake ring undergoes a discrete axial displacement to a new axial position at which the brake ring remains upon cessation of the downward axial pressure thereon, whereby each twist spindle includes a yarn intake conduit and has associated therewith a respective yarn balloon guide disposed above the yarn intake conduit, the method comprising: on a support frame to which the yarn balloon guides are mounted and which is displaceable upwardly and downwardly parallel to the hollow axes of the twist spindles, exerting a downward axial force such that the yarn balloon guides mounted to the support frame simultaneously exert downward axial pressure on the yarn intake conduits of the twist spindles which, in turn, effects axial displacement of the rotatable and axially adjustable brake ring on the yarn intake conduit of each twist spindle into new axial positions, whereby a simultaneous adjustment of the braking force applied by the twist spindles to the yarn traveling therethough can be accomplished.
 2. An apparatus for simultaneously commonly adjusting the braking force of a plurality of capsule-like yarn brakes each disposed in a respective twist spindle of a two-for-one twisting machine, each twist spindle having a yarn brake supported by two axially spaced brake rings in the hollow shaft of the twist spindle, the one brake ring being rotatable in response to axial pressure thereon whereby the rotation of the brake ring effects a discrete axial movement of the brake ring into a new axial position at which the brake ring remains once the axial pressure thereon ceases, each twist spindle having a yarn intake conduit forming a portion of its hollow shaft, and the two-for-one twisting machine having a plurality of yarn balloon guides each associated with a respective twist spindle for guiding the formation of a yarn balloon relative thereto, the apparatus comprising: means for mounting to the yarn intake conduit of each respective twist spindle the respective brake ring of the twist spindle, the brake ring being that brake ring whose rotation is translated into axial displacement of the brake ring; and a support frame movably mounted on the two-for-one twisting machine for movement upwardly and downwardly generally parallel to the axes of the twist spindles, the plurality of yarn balloon guides being mounted to the support frame such that each of the yarn balloon guides exerts, simultaneously with the other yarn balloon guides, a downward pressure on the yarn intake conduit of the respective associated twist spindle, whereupon simultaneous downward axial pressure is thereby applied to the brake rings mounted to the yarn intake conduits of the twist spindles in a manner which causes the one brake rings thereof to rotate and undergo the associated axial displacement.
 3. An apparatus according to claim 2 and further comprising a plurality of adjustment units each associated with a respective twist spindle and a plurality of radially projecting detents each mounted in the hollow shaft of a respective twist spindle and projecting radially inwardly toward the respective associated adjustment unit, each adjustment unit having an annular upper toothed rim and an annular lower toothed rim, the upper toothed rim having a plurality of downwardly oriented teeth distributed around its circumference such that downwardly opening slots are formed between adjacent teeth and the lower toothed rim having a plurality of upwardly oriented teeth distributed around its circumference such that upwardly opening slots are formed between adjacent teeth, the teeth of the upper toothed rim and the teeth of the lower toothed rim, in response to the downward axial pressure on the yarn intake conduit, cooperating with one another to engage the respective radially inwardly projecting detent such that the adjustment unit is guided by the stationary detent to rotate in a given rotational direction relative to the stationary detent, the apexes of the teeth of the upper toothed rim being angularly offset from the apexes of the teeth of the lower toothed rim, and respective flank surfaces of the teeth of the upper toothed rim and respective flank surfaces of the teeth of the lower toothed rim being angled at a selected one of an upward angle and a downward angle relative to the given rotation direction such that the teeth of the upper toothed rim and the teeth of the lower toothed rim guide the rotational movement of the adjustment unit relatively along the stationary detent in a manner such that the stationary detent is unseated from a respective notch between the teeth of the lower toothed rim and is subsequently seated in another notch between the teeth of the lower toothed rim upon the cessation of the downward axial pressure on the yarn intake conduit.
 4. An apparatus according to claim 3, wherein those flanks of the teeth of the upper and lower toothed rims which are angled upwardly relative to the rotational direction extend substantially in the axial direction.
 5. An apparatus according to claim 3, wherein the angled flank surfaces of the upper and lower rims form an angle of approximately 45° with the rotational direction.
 6. An apparatus according to claim 2, wherein a spring is provided which operates against the lower toothed rim of the adjustment unit so as to bias the adjustment unit axially upwardly, whereby the upward axial bias of the adjustment unit effects seating of the detent in the next notch of the lower toothed rim upon the cessation of the downward axial pressure on the yarn intake conduit.
 7. An apparatus according to claim 2, wherein each of the toothed rims is configured as a lower component freely rotatable relative to the other portion of the adjustment unit, the toothed rims being non-adjustable in the axial direction.
 8. An apparatus according to claim 2, wherein the yarn balloon guides are configured as ball-shaped yarn balloon guides which are each centered on the yarn intake conduit of the respective associated twist spindle. 